Process for coating fabrics with rubber



Patented Sept. 24, 1940 Stewart R.'0gilby, Staten Island, N. Y.,assignor to United States Rubber Company, New York, N. Y., a corporationof New Jersey N Drawing.

Application April 7, 1939,

Serial No. 266,535

6 Claims.

This invention relates to aprocess for coating fabrics with rubber, andmore particularly. for coating fabrics directly from latex.

In coating fabrics directly from latex, it is very desirable to use aheat sensitive latex composition so that on raising the temperature ofthe latex after spreading, as in the early stages of a drying operation,the latex will set to a gel and prevent striking through of the latexand the consequent marring of the, appearance .of the un-.'

treated surface of the fabric. In producing dyed fabrics having a rubbercoating thereon, it is:-' often desirable and in some casesnecessary't'o apply the rubber to the fabric before the dyeing have beenso compounded as to be capable of gelling on heating are alkaline incharacter and leave a final rubber deposit on the fabric having analkaline reaction. Dye baths for fabrics are often neutral or slightlyacid and when a fabric coated with rubber which has an alkaline reactionis introduced into sucha dye bath, the alkaline reaction of the rubbermay oftentime change the pH of the bath sufliciently to give off-colorsin the final dyed fabric.

According to the present invention, fabrics may be coated with a latexcompositionwhich is heat sensitive and which has an acid reaction sothat on the gelling, or the gelling and drying, of such a latexcomposition on a fabric,-the deposit will have an acid or neutralcharacter and hence not detrimentally affect the color of the dyedmaterial by raising the pH, as in the case of a rubber deposit having analkaline reaction.

I have found that a latex composition stabilized by the addition to thelatex of a condensation product of a straight chain aliphaticalcohol-having at least six carbon atoms with a polyglycol compoundcontaining at least four ethenoxy groups may be made heat sensitive byadjusting its pH to below 7. The commercial name of one of suchcommercial products is Emulphor-O, believed to be the condensationproduct of tetraethylene glycol with oleyl alcohol. It has been foundthat up to 5% of Emulphor-O, for example, permits a latex composition ofover 30% solids content to be acidified as faras a pH of 1, and yet theEmulphor-O will lose its power to protect the latex at elevatedtemperatures and the latex composition will gel on heating.

The present invention may be utilized in the manufacture of varioustypes of fabrics, some or all of whose threads or yarns are to be dyed55 after coating with the latex composition. In

operation. Commonly, latex compositions which these cases, there is noresidual alkalinity in the latex gel, or the dried rubber deposit toproduce off-colors in the dyeing operation. The present invention mayalso ,be applied to the coating of fabrics where the fabrics are not tobe dyed after coating, but where it is desired that the spread latex orthe final rubber coating'have an acid or neutral reaction. If the pH ofthe latex, according to the present invention, is lowered below i 7 bythe addition of a volatile acid, then the 10 .latex after gelling willretain an acid reaction,

but on drying the rubber deposit will be neutral.

The present invention is of particular advan- :-tage in the manufactureof pile fabrics where the pile is looped around threads in a woventextile backing and the piles are anchored to the backing by means of arubber coating or deposit. Such pile fabrics are commonly'woven on thesocalled double plush principle, where two textile backings or groundfabrics are woven with pile warps looped around weft threads in eachbacking and where the piles are cut intermediate the two backings toproduce two pile fabrics. In upholstery fabrics of suchconstruction, thetextile backing is usually woven of cotton yarns and I these, ifdesired, may be predyed before weaving. The pile warps are commonlyanimal hair and these are generally dyed after the woven and splitfabrics have been treated with latex according to the present invention.In carrying out the present invention with reference to such pilefabrics, the heat sensitive latex having a pH below 7 and capable ofgelling at an elevated temperature, is spread onto the back of the pilefabric as by means of a spreader knife or by spraying or in any desiredmanner. Only suflicient latex need be applied to satisfactorily anchorthe piles to the ground fabric after drying of the rubber film. Thelatex may be scraped onto the back of the pile fabric in such a mannerthat the tips of the pile bights will project from the final rubbercoating, as in the present practice of making this type of upholsteryfabrics. After spreading the latex compound, the deposit is heated to atemperature sufiicient to gel the latex 5 whereby striking-through ofthe latex on further treatment is prevented. In that the latex will notstrike through after gelling, the gelled latex need not be dried beforesubsequent aqueous treatments. It is preferred, however, todry thefabric before dyeing and finishing, and in such case the fabric needonly be passed into a drier after being spread with latex and thegelling will take place in the first stages of the drying operationwhere, as is generally the case, the tem- I may dye both the piles andthe ground fabric.'

The following formula is illustrative of a latex composition which maybe used for anchoring mohair piles to a cotton ground fabric in a pilefabric woven on the double plush principle:

Parts by weight Rubber 100 Latex Water 62 aqueous solution of Emulphor-O12 15% aqueous solution of acetic acid 25 The above latex compound has apH of 4.4 and a dried rubber film deposited from it has a neutralreaction due to the volatilization of the acetic acid on drying. Thislatex is fluid at ordinary room temperatures and will gel attemperatures of 85 C. or above. It is thus only necessary to spread thelatex compound on the back of the pile fabric at temperatures below thegelling temperature, and after spreading to pass the spread fabricthrough a conventional drier having a temperature greater than 85 C. atits entrance so that the latex compound will gel in the first stages ofthe drying operation, and the further heating of the gel to dry the samewill evaporate water from the gel without the rub ber particles whichare no longer mobile striking through and marring the face of thefabric. Various other compounds may be used, and the latex may beunvulcanized or vulcanized as desired.

In view of the many changes and modifications that may be made withoutdeparting from the principles underlying the invention, reference shouldbe made to the appended claims for an understanding of the scope of theinvention.

Having thus described my invention, what I claim and desire to protectby Letters Patent is:

1. The process of coating. a fabric with rubber which comprises applyingto a fabric a fluid latex composition having a pH below '7 andcontaining a condensation product of a straight chain aliphatic alcoholhaving at least six carcapable of gelling at elevated temperature,heating the applied latex composition to a temperature sufficient to gelthe same, and drying.

gelling at elevated temperature, heating the applied latex compositionto a temperature sufficient to gel the same, and drying.

3. The process of producing a dyed fabric with a rubber coating thereonwhich comprises applying to an undyed fabric a fluid latex compositionhaving a pH below 7. and containing a condensation product of a straightchain aliphatic alcohol having at least six carbon atoms with apolyglycol compound containing at least four ethenoxy. groups, saidlatex composition being fluid at room temperature and capable of gellingat elevated temperature, heating the applied latex composition to atemperature sufficient to gel the same, and dyeing the coated fabric.

4. The process of producing a dyed fabric with a rubber coating thereonwhich comprises applying to an undyed fabric a fluid latex compositionhaving a pH below 7 and containing Emulphor-O, said latex compositionbeing fluid at room temperature and capable of gelling at elevatedtemperature, heating the applied latex composition to a temperaturesuflicient to gel the same, and dyeing the coated fabric.

5. The process of making pile fabric which comprises weaving a textilebacking with undyed pile warps looped therein, applying to the backingand pile loops a fluid latex composition having a pH below 7 andcontaining a condensation product of a straight chain aliphatic alcoholhaving at least six carbon atoms with a'polyglycol compound containingat least four ethenoxy groups, said latex composition being fluid atroom temperature and capable of gelling at elevated temperature, heatingthe applied latex composition to a temperature sufllcient to gel thesame, and dyeing the coated fabric.

6. The process of making pile fabric which comprises weaving a textilebacking with undyed pile warps looped therein, applying to the backingand pile loops a fluid latex composition having a pH below 7 andcontaining Emulphor- 0, said latex composition being fluid at roomtemperature and capable of gelling at elevated temperature, heating theapplied latex composition to a temperature suflicient to gel the same,and dyeing the coated fabric.

STEWART R. OGILBY.

